<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      main,
      aside {
        height: 100px;
      }
      main {
        background-color: #f09e5a;
      }
      aside {
        background-color: #c295cf;
      }
      .wrap {
        display: flex;
        flex-direction: row-reverse;
        flex-wrap: wrap;
      }
      .main {
        flex: 1;
      }
      .aside {
        /* flex: 1; */
        width: 200px;
      }
      @media only screen and (max-width: 1000px) {
        .wrap {
          flex-direction: row;
        }
        .main {
          flex: 100%;
        }
      }
    </style>
  </head>
  <body>
    <div class="wrap">
      <main class="main">主要布局容器</main>
      <aside class="aside">次要布局容器</aside>
    </div>
  </body>
</html>
